[2004-2007] [PC. Windows XP] Game I've played long time ago about a lab full of aliens and monsters

I'll say everything I remember about this top-down type game... The menu screen had green and white pallet colors, the game starts outside a lab where the player shoots aliens and guards in order to achieve I don't know what 'cause last time I've played this game I was like 8-10yo Other thing is the operational system I used to play this game was windows XP. That's all I remember for now. PLEASE help me find this